The present invention relates generally to orthopedic surgical procedures, and more particularly to a method and apparatus for an external fixation of bones.
In various orthopedic surgical procedures, it is necessary to secure two or more portions of bone in a relatively fixed relationship to each other. This need is often a result of a fracture which has occurred to the bone. To ensure that the bone can properly regenerate and fuse the fractures of the bone, it is important that the various bone portions be fixed at the desired position during bone regeneration.
Various external fixation devices for the repair of traumatized bone are known. For example, U.S. Pat. No. 5,620,442 to Bailey et al. discloses an apparatus for the external fixation of small bones. The apparatus is illustrated to include a first bone screw clamp for receiving a first bone screw which is connected to a first bone portion. The external fixator further includes a second bone screw clamp which is operable to receive a second bone screw connected to the second bone portion. The first and second bone screw clamps both include a spherical portion. The external fixator further includes a connection member for securing the spherical portions of the bone screw clamps. The connection member defines a radiographic window to permit radiographic examination of the bone fracture without removing the apparatus. U.S. Pat. No. 5,620,442 is hereby incorporated by reference as if fully set forth herein.
While known fixators, including the type described above, have proven to be effective in fixating bones, they nevertheless can be the subject of certain improvements for particular external fixation applications.
According to one aspect, the present invention relates to a fixator operable for securing two portions of bone in a fixed relationship to each other, with the first bone portion having a first bone screw attached thereto and the second bone portion having a second bone screw attached thereto. The fixator generally includes a bone screw clamp assembly having a base and a cap member that define a cavity receiving a compressible spherical member. A connecting rod passes through the spherical member. Selected movement of the cap member relative to the base arrests relative movement between the pin clamp assembly and the connecting rod.
One particular advantage of the present invention is the provision of a method and apparatus for the external fixation of bones that allows universal adjustment of a bone screw clamp assembly about a point through which a connecting rod passes.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention.